The other day while my two boys were at school, I forced myself to conduct a pretty creepy experiment. First, I went online and checked out a few of the estimated 4.2 million pornographic sites on the Internet. Next, I visited one of those sex chat rooms that randomly pair you with someone else for a webcam-based conversation and witnessed the extreme things people are doing in full view of total strangers. Then I imagined being a kid—and how I would've reacted if this had been the first graphic sexual imagery I'd ever seen.

After I completed this challenge, my blood pressure was in the stratosphere, and I was more than a little freaked out. What's shocking is how insanely easy it is for anyone—including kids—to enter this world without registering or paying for a thing. But cyberporn is a fact of life for kids today: Fifty-three percent of boys and 28 percent of girls between the ages of 12 and 15 deliberately seek out sexually explicit material, much of it online, according to a recent survey. That's not to mention the leagues of minors who are exposed unintentionally each year, whether through sexting or clicking on links in spam or logging onto sites with deliberately misleading domain names. "The idea of kids looking at racy images is nothing new," says Jane D. Brown, Ph.D., a professor at the School of Journalism and Mass Communication at the University of North Carolina at Chapel Hill. "What's different now is that the Internet, cell phones and digital cameras have made pornography, much of it hard-core and violent, more accessible to younger people than ever before."

Given this disturbing reality, it's the responsibility of all parents to protect their kids not only by supervising their activities online, but also by teaching them what a healthy, loving relationship actually is. "Living in such a wired, communication-rich environment may be what finally forces people to talk to their kids about cyberporn and so many other difficult but important issues," says Ralph DiClemente, Ph.D., professor of public health at Emory University in Atlanta. "If you think about it, there's a silver lining here."

The New Normal

Before the Internet, studies indicated that people who looked at a lot of erotica built up a tolerance, driving them to seek out more extreme and explicit materials. "These days the Web—with its virtually unlimited content, variety and anonymity—feeds that compulsion in a way that, say, a magazine never could," says DiClemente.

Even so, the vast majority of adolescents exposed to cyberporn don't become addicted. "There's no data showing a huge catastrophe here," J. Dennis Fortenberry, M.D., professor of pediatrics at Indiana University School of Medicine. "Most young people will see and interact with Internet pornography—just like they'll experiment with other electronic media—and move on."

The small percentage of kids who end up developing psychological problems are generally those with preexisting addictive tendencies or compulsions. Other factors, including boredom, social isolation and depression, can also increase a child's vulnerability, according to Stephen Schultz, a partner at the Oxbow Academy residential treatment center for teen sex addiction located in Wales, Utah.

But there are troubling signs that regular exposure can affect what experts call the "adolescent's sexual script." In other words, kids may come to believe that what they're seeing online is normal or at least acceptable. Because Internet porn seldom reflects realistic interaction between partners, kids who see a lot of it are more likely to dissociate sex from intimacy, according to research done at the University of Amsterdam. Both males and females also appear to have distorted views of sexual gender roles in real life. "Girls are more inclined to be submissive because that's how women are usually portrayed," says Brown. Her work also suggests that boys who watch porn from a young age are more likely to harass others, and that adolescents who frequently view explicit erotica tend to start having intercourse earlier. Still, she and other experts can't say whether it is the cause of such behaviors. "Most likely, it doesn't create problems but can trigger a downward spiral for kids who are already inclined that way," says Brown.

Here's the good news for parents everywhere: No matter how pervasive or accessible, the Internet is not the most powerful determinant of adolescent sexual behavior, and you can take steps to shield your kids from cyberporn. "For the past six years we've surveyed teens and they consistently tell us that it's their parents—not their peers or popular culture—who have the greatest influence on their decisions about sex," says Bill Albert, chief program officer at the National Campaign to Prevent Teen and Unplanned Pregnancy in Washington, D.C. "The closest thing we have to a magic bullet is parents and children working together to create a connected, communicative family."

Step 1: Stay Aware

Understanding your teen's virtual reality is a good place to start. That doesn't mean becoming a Facebook fanatic or cyberspy, but you should have a clear idea of what he's doing and where he's going, says psychologist Larry D. Rosen, Ph.D., author of iDisorder: Understanding Our Obsession with Technology and Overcoming Its Hold on Us (Palgrave Macmillan). Have him show you his Facebook or Twitter page, and ask if students at school are sexting or visiting explicit sites—and what he thinks about it. "You've got to know enough about his online activities before you can talk about them in a meaningful way," says Rosen. Checking out the pictures he's posted on Facebook, for example, can lead to an informal chat about which ones are appropriate and why.

Step 2: Play Interference

There are many tools parents can use to limit kids' access to porn sites, such as checking their Internet histories and installing filtering software that blocks sexually explicit material. Just keep in mind that they're not foolproof. "Filters have their value, especially when it comes to protecting young kids from accidental exposure. But if teens want to access sexual material, they'll find a way around whatever barriers you've created," says Eva S. Goldfarb, Ph.D., professor of health education at New Jersey's Montclair State University.

Some parents require kids to keep their bedroom doors open while on the Web. Others require that laptops and desktops be out in the open, in places like the kitchen or den. "It ultimately comes down to what works best for your family and your house," says Rosen. "The point is to not let your kids hole up quietly in their rooms. It's tempting, since a quiet teen seems like an easy teen. But over the long term, it's asking for trouble."

Step 3: Start a Dialogue

Despite even the best efforts, your kids will probably be exposed to cyberporn, if they haven't been already. And it's happening a whole lot earlier and with greater frequency than most parents realize. All of which underscores the importance of talking to your teens and laying a strong foundation for a healthy attitude about sex. Psychoanalyst Paul Joannides, Psy.D., author of Guide to Getting It On (Goofy Foot Press), puts it even more bluntly: "If you don't teach your kids about sex in this day and age, porn and the media will."

Ideally, there should be an ongoing, age-appropriate discussion that evolves over the years, says Albert. Not "The Talk" many of us had with our parents when we were kids, which was probably stilted, awkward and quickly dismissed. "Think of it more as an 18-year conversation," says Albert, pointing out that opportunities for parents to get the conversation started are everywhere. With tweens and teens, the sheer overabundance of sex on television, at the movies and in the news provides a convenient way in. Next time you're watching something together and see people jumping into bed, ask your teen if she thinks they're making the right decision and why. Raise the issue of contraception, condoms and responsibility. If there are blaring headlines about a sexual assault, bring up the matter of mutual consent.

Make clear what your personal values are—such as whether sex should only take place in a loving relationship or after marriage—and the reasons why you feel that way. Try not to shy away from specifics like masturbation, which for most kids is the first sexual experience they're going to have.

And don't just dwell on the downside. It's perfectly fine to discuss the joy of sex, both physical and emotional. "Parents are uncomfortable and afraid to talk with their kids about how pleasurable and fun sex is," says Joannides. "But when we're open with our children, they'll ask us the questions that are really on their minds and decide we're the ones they can turn to."

Worst-Case Scenario

You've had dozens of discussions with your tween or teen about Internet porn. You've supervised, monitored, checked browser histories and thought all was well. Then you receive a call from his best friend's mom, who has just caught the boys online at a XXX-rated site.

Don't panic. Take a deep breath and tell yourself that this unwelcome discovery opens the door for yet another positive exchange. When your child gets home, ask how he got to the site. By accident? Lured by spam or pop-up ads? Was he already familiar with the destination?

Even if it's the latter, hold your temper and turn the talk into a teaching moment. Acknowledge that sexual curiosity is natural, and that with so much pornography online, it's tempting to search it out.

"Remind your child—yet again—that the images he's seen do not depict what sex in a relationship is actually like, and that the sex portrayed is often exploitative and harmful to women," says Eva Goldfarb. You might even offer to get some educational books about sex that are geared for teens.

Fact is, no matter how hard we try, we can never totally control what our kids do online. But they are far better off being informed and forewarned, and that's worth whatever embarrassment or discomfort it may cause you. "When children feel connected to their parents and have had conversations with them about their sexual beliefs, it matters," says Jane Brown. "It really does."